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 A193109 Least k such that 2^x + k produces primes for x=1..n and composite for x=n+1. 0
 0, 1, 9, 3, 225, 15, 65835, 1605, 19425, 2397347205, 153535525935 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS All terms except the first four are congruent to 15 mod 30. a(10) was found in 2005 by T. D. Noe and a(11) was found in the same year by Don Reble. Other known values: a(13)=29503289812425. LINKS MATHEMATICA Table[k = 0; While[i = 1; While[i <= n && PrimeQ[2^i + k], i++]; i <= n || PrimeQ[2^i + k], k++]; k, {n, 9}] (* T. D. Noe, Jul 21 2011 *) CROSSREFS Another version of A110096. Cf. A092506, A057733, A104070, A144487, A008597. Sequence in context: A248311 A038293 A119516 * A242069 A197828 A116393 Adjacent sequences:  A193106 A193107 A193108 * A193110 A193111 A193112 KEYWORD more,nonn AUTHOR Arkadiusz Wesolowski, Jul 21 2011 STATUS approved

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Last modified February 21 12:27 EST 2018. Contains 299411 sequences. (Running on oeis4.)